类高尔夫球表面处理对受电弓气动噪声的影响

针对高速列车弓网噪声,为降低主要由细长圆柱杆件构成的受电弓的气动噪声,建立三维圆柱绕流气动噪声分析模型,基于大涡模拟方法、声类比理论模拟圆柱杆件的流场特征,分析远场气动噪声频谱特性与分布规律,并对圆柱杆件表面作球缺型凹坑处理,分析表面处理方案的降噪效果。数值结果表明,来流与圆柱轴向所在平面法向的气动噪声受升力波动影响,声压级最大;圆柱来流方向前后气动噪声受阻力波动影响,声压级最小。圆柱表面球缺型凹坑处理方式可以有效降低圆柱杆件远场R=5 m处最大声压级,凹坑加密,降噪效果更好,优化模型II-1、II-2和II-3在R=5 m处最大声压级分别降低1.5 d B、1.9 d B和2.4 d B。相关结果可为高速列车噪声控制提供参考。

Study on the Effect of Golf-like Surface Treatment on Pantograph’s Noise

For reducing the aerodynamic noise of pantographs installed on high speed trains mainly consisting of elongated cylindrical rod, a three-dimensional geometric model of cylindrical rod was developed to simulate the flow field around the rod and analyze the spectrum characteristics and distribution of the far field aerodynamic noise based on the large eddy simulation method and the acoustic analogy theory. The surface of the cylindrical rod was treated with dimples to analyze the noise reduction effect of the treatment scheme. Numerical results show that the aerodynamic noise in the normal direction of the flat surface which contains cylinder axis and the velocity is affected by the lift force fluctuation, and the sound pressure level is the maximum. The aerodynamic noise in the direction of velocity is affected by the drag force fluctuation, and the sound pressure level is the minimum. The treatment scheme can effectively reduce the maximum sound pressure level at the field 5 meters away from the cylindrical rod. The effect of noise reduction get better with more dimples used in rod’s surfaces. The maximum sound pressure levels of the optimized model II-1, II-2 and II-3 are reduced by 1.5 dB, 1.9 dB and 2.4 dB. The results can provide a reference for control of high-speed train noise.